1. Field of the Invention
The present invention relates to a series of silicone containing glycosides prepared by the reaction of a hydroxy containing silanol with a reducing saccharide, or a source of reducing saccharide, in the presence of a suitable catalyst. The invention also relates to the application of these novel compounds in personal care compositions for use on hair and skin.
2. Related Art
The reaction of a reducing saccharide, e.g. an aldose or ketone saccharide, or a source thereof, with an alcohol results in the formation of a glycoside. Acid catalysts are used to promote the reaction between the reducing saccharide and the alcohol. When the alcohol is an alkanol, the resulting glycoside is an alkyl glycoside. Alkyl glycosides are known to those skilled in the art.
Alkyl glycosides are surface active materials which have been known for many years. They are synthesized by the reaction of a saccharide, most importantly glucose with a fatty alcohol. They have been known since the early 1900's having been described by Emil Fischer. When the sugar used is a saccharide like glucose, the resulting material is correctly called a glycoside, however when a polysaccharide is used like starch is used as a raw material, the resulting compound is more contains some alkyl glycoside and some material which more correctly is referred to as polyglycoside. Common usage however allows for either materials to be referred to as a "glycoside". The reaction of the hydroxyl group in the alcohol with the saccharide results in an ether linkage. Much work has been done recently to improve purity, color, and reduce odor and by product levels in alkyl glycosides.
U.S. Pat. No. 3,547,828 issued to Mansfield et al. discloses a process for producing alkyl glycosides which possess surface activity by reacting a saccharide with a lower alkanol (butanol) in the presence of an acid catalyst, then reacting again with a higher alkanol to produce the desired higher alkyl glycoside.
U.S. Pat. No. 5,003,057 issued to Mc Curry et al., which is incorporated herein by reference, discloses a alternate process for producing the higher alkyl surface active glycosides.
The parent application for which this is a continuation in part teaches the preparation of a glycoside based upon dimethicone copolyol. The dimeticone copolyol contains ethylene oxide and results in water soluble materials. The compounds of the present invention is based upon silanols and consequently are water insoluble.
While these patents deal with interesting process modifications by which higher purity, lighter color and simpler process technology can be used to produce alkyl glycosides, none address the potential of incorporating into the molecule a silicone portion which results in unique solubility, substantivity and lower irritation properties of the glycoside class. While Mc Curry states (col 1 line 21) that these materials (alkyl glycosides) contribute surface activity, e.g. detergency, the added advantages of incorporation of silicone into the molecule has been heretofore unappreciated.